盐胁迫对5份无芒雀麦苗期生长和生理生化的影响及综合性评价

为了明确不同无芒雀麦苗期耐盐能力的强弱，本研究选择5份不同株型的无芒雀麦作为供试材料。根据新疆土壤盐碱成分设置中性盐(M盐)：NaCl∶Na₂SO₄∶Na₂CO₃=1∶4∶0和碱性盐(A盐)：NaCl∶Na₂SO₄∶Na₂CO₃=1∶1∶8两种处理，于三叶期每盆一次性浇灌2 L电导率(EC)为20 ms·cm^-1的盐处理液，CK浇灌等量自来水。处理30 d后测定生长指标、叶绿素荧光特性参数、丙二醛(MDA)和渗透调节物质含量，并通过相关性分析、主成分分析、隶属函数分析对13个指标进行分析评价。结果表明：除F_v/F_m和F_v/F_o外，盐胁迫显著影响其余11个指标，且5份材料间差异显著(P<0.05);5份无芒雀麦的株高、茎粗、分蘖数、地上生物量、根冠比、MDA和脯氨酸含量在不同盐胁迫下表现出不同的适应变...

Effects of salt stress on the growth， physiology， and biochemistry of five Bromus inermis varieties

The aim of this study was to compare the salt tolerance of different Bromus inermis varieties. Seedlings of five B. inermis varieties （L_1-5） were used as the experimental materials. According to the composition of soil salts in Xinjiang， two treatments were established； neutral salt （M salt） （NaCl∶Na₂SO₄∶Na₂CO₃=1∶4∶0） and alkaline salt （A salt） （NaCl∶Na₂SO₄∶Na₂CO₃=1∶1∶8）. When seedlings reached the three-leaf stage， each pot was irrigated with 2 L salt treatment solution with an electrical conductivity （EC） of 20 ms·cm^-1 at a one-time treatment. The control （CK） was irrigated with the same amount of tap water. After 30 days of treatment， the growth index， chlorophyll fluorescence characteristic parameters， malondialdehyde （MDA） content and osmoregulation substance content were measured. Then， correlation analysis， principal component analysis， and a membership function analysis were used to analyze and evaluate 13 indicators. The results showed that， other than maximum quantum efficiency （F_v/F_m） and potential quantum efficiency （F_v/F_o）， the other 11 indexes were strongly affected by salt stress， and the values of the indexes differed significantly among the five Bromus varieties （P<0.05）. The plant height， stem diameter， tiller number， aboveground biomass， root-crown ratio， MDA content， and proline content of the five B. inermis varieties showed different adaptive changes under different types of salt stress. The plant height of L₂ and L₄ was significantly higher in the A salt treatment than in the M salt treatment； the A salt treatment significantly increased the aboveground biomass of L₃， while the M salt treatment had no significant effect compared with CK. The MDA content of L₁， L₂， and L₅ increased more under the A salt treatment than under the M salt treatment， and the MDA content of L₂ was higher than that in the other lines under the A salt treatment. Salt stress seriously inhibited root development and the accumulation of soluble sugars in all B. inermis varieties. The underground biomass and soluble sugar contents in the five B. inermis varieties were decreased to varying degrees in the salt treatments compared with CK. A principal component analysis showed that osmotic adjustment substance content and growth indexes could be used as comprehensive indexes of the salt tolerance of B. inermis. According to the salt tolerance evaluation D value， L₄ has strong salt tolerance and L₅ has weak salt tolerance.